In the case of gas turbines, the so-called surge limit marks the smallest possible gas flow at a given pressure increase at which the compressor can still be operated in stable fashion. In the event of a collapse of the entire compressor flow, the pressure normally built up behind the compressor discharges abruptly forward in the direction of the low pressure. Subsequently, another gas intake by the compressor occurs until it comes to another abrupt pressure decrease. This process is called as “compressor pumping”. Such “compressor pumping” must be prevented by all means in gas turbines, particularly in the case of aircraft gas turbines, since the compressor as well as downstream components of the gas turbine, namely the combustion chamber and the turbine, may be damaged in the process. Therefore, an extension of such surge limits is desirable. In this context is has been shown that a surge limit expansion is possible by injecting air into the blade tip area of a turbo compressor. In order to realize this injection, a supply of air is required under high pressure into the housing of the compressor from outside. This air must then be transported through nozzles in targeted fashion from the housing into the flow channel which usually occurs through slotted housing segments. In this context, in the case of a compressor housing commonly designed in clamshell fashion, a circumferential pressure compensation space, a so-called plenum, in the housing is subjected to pressure and the air is then fed into the flow channel through the aforementioned housing segments equipped with shaped slots or nozzles.
However, the disadvantage of these known compressor housings is the necessary sealing between the individual housing segments, for example by means of sealing plates, which, however, will not ensure a perfect sealing. In addition, the housing segments are subjected to a great pressure differential between the pressure compensation space and the flow channel, requiring a relatively strong structural design of the housing segments and a correspondingly great weight.